Grate for underfeed stokers



Sept. 5, 1939. PELTZ Q 2,171,862

GRATE FOR UNDERFEED STOKERS Filed April 3, 1957 37m? J6 as 7 J6 9L INVENTOR. M. PE LTZ ATTORNEY.

Patented Sept. 5, i939 PAT N OFFICE ens'rn FOR UNDERFEED s'ronnns Gordon M. Peltz, Portland, reg., assignor to Iron Fireman Manufacturing Company, Portland, Oreg.

Application April 3, 1932, Serial No. 134,786

4 Claims.

This invention relates generally to underfeed stokers, and particularly to a grate therefor.

The main object of this invention is to construct a form of pin holegrate for underfeed I stokers by means of which air will be so delivered to the fuel bed as to make it accessible to every portion of the fuel bed in the shortest possible time.

l The second object is to accomplish this result Fig. 2 is a fragmentary elevation showing por-f tions of three of the grate-sections with the intermediate section cross-hatched for the sake of clearness.

25 Fig. 3 is a fragmentary perspective showing the manner in which the grate sections engag each other.

Fig. 4 is a horizontal section taken along the line 4-4 in Fig. 1. 30 Similar numbers of references refer-to similar parts throughout the several views. 1 Referring in detail to the drawing, there is shown a retort base Ill withinwhich is contained the retort II which. communicates by means of 35 a coal tube l2 with a coal supply section not -shown. A worm it conveys fuel through the tube l2 into the .retort II. The retort II has a circular opening I in the center of the top II 0f the base In.

. Mounted on the top 15 is a grate casing It whose under side H is provided with spokes l8 which terminate in the lowermost 'grate section I! which is concentric with the opening ll.

Bolts 20 secure the grate casing It to the base I2. Air enters the retort base It through the opening IA and escapes therefrom through the opening lllB into the space IIC.

The position of the toothed wheel 2| which carries a clinker breaking bar (not shown) is in- 50 dicated. The wheel 2! is revolvable on the cylindrical portion 22 of the casing l6. It is desirable to provide the under side ll of the casing I with an annular'tonguen which extends into a sealing groove 24 to the top II. The upper- (Cl. ice-14s) a and provided with a sealing groove 26 and bolt holes 21.

Referring more particularly to the. grate sections, it will be seen that the lowermost section I! has formed 'on its top side the sloping slots 5 28. These slots '28 have between them the raised lands 29 which are approximately one-third as wide as the slots 28. The lands 28 are of uni-. form width and are equally spaced.

Superimposed above the section l9 are the 10 various grate sections 30, each of which has formed-on its upper side the slots 28 and the lands 29. Each section 30 has also formed on its under side the radial slots 28L and lands 29L.- In Figs. 2, 3 and 4 are clearly shown the manner 16 in which the raised lands or lugs '29 and 29L .occupy their respective slots 28L and 28. The

shape of the parts is suchas to readily permit their reproduction by casting same in sand.

It will be noted in Fig. 3 that the inner end 3| 20 of each downturned land 29L is made approximately vertical in order to eliminate the necessity of casting sharp points. The same is true of the outermost end 22 of each upturned land 29. It wilLbe observed that the faces 33 and 34 25 of the slots 28 and 28L and the lands and 29L slope downwardly toward the vertical axis of the retort. Naturall this slope decreases toward the uppermost tion 30 where it is sub- 0! the fire pot. It will be noted that when the parts are thus superimposed, there is formed a plurality obair spaces 25 on each side of each land 29 and 29L, each of which has a smaller area than would be obtainable if the slots were cast directly in the parts.

By this method air is delivered to the combustion in a great many small streams without the; necessity of employing parts which are diflicult to make and more dimcult to maintain when 0 made.

It will be noted in Fig. 4 that the raised-lands or lugs 36 are somewhat wider than are the lugs 29. The opposite faces 21 of each. pair of lands- 36 are so spaced as to engage th'opposite faces 21L of the corresponding slots 22L. It is desirable to provide at least three pairs of lugs 2.6 in

'order to insure the proper centering of each grate section 32. This also prevents the relative rotation of the sections 30. This is important since if the sections 20 were permitted to rotate with relation to each other, they would cause a variation in the sizes of the. air spaces 35.

Above the uppermost grate section 30 is placed an outwardly turned iire pot rim 28 which is u held down by a ring 39 by means of the bolts 40 which extend through the portion of the casing Hi.

It may be seen from the foregoing that by this construction it is 'possible to deliver to the fire a 36 which prevent the relative rotation of adjacent grate sections 30. The lugs 36-also insure the vertical alinement of the parts by centering them about the vertical axis of the retort.

'It isimmaterial how a section is placed upon the next section below as long as they are approximately in vertical alinement since the downwardly extending lugs of one section will fit properly between the upwardly extending lugs of the next lower section regardless of the relative positions to which these parts are rotated.

While I have illustrated these sections as having the thickened lugs 36 on the top side, it will be understood that they could also be placed on the bottom side without departing from the spirit of the invention.

Throughout the specification I have referred to the slots and lands as being radial and I have so illustrated them. These could, of course,- depart from radial lines without detracting from the usefulness of the device.

I am, of course, aware that numerous forms of sectional grates have been constructed in the past. It is, therefore, not my invention to cover such devices broadly but I do intend to cover all such forms and modifications thereof which fall fairly within the appended claims.

I claim:

1. A plurality of superimposed outwardly flaring grate rings, the upper and lower sides of which are provided with substantially radial slots having raised lands between same, the lands of one ring being capable of registering with the slots of an adjacent ring, the slots having a considerably greater width than do said lands, the purpose of which is to permit each land to divide. its related slot into. two small slots and means for preventing the relative rotation of the respective grate ring elements.

2. A pair of superimposed outwardly flaring grate rings, the top of the lower ring and the bottom of the uppr ring having wide radial slots formed therein between which are relatively narrow lands, said lands including a plurality of pairs of lugs whose adjacent sides are spaced to engage the opposite faces of a pair of lands forming a part of the adjacent grate ring. r

3. A pin hole grate consisting of a plurality of superimposed circular sections, the engaging faces of which have wide radial slots formed therein forming relatively narrow lands therebetween,

the lands of one section; being adapted to register with the slots of an adjacent section and having means for holding the lands of one grate ring substantially in the center of the slots of an ad- 1 jacent ring and means for holding said rings in concentric relationship.

4. A grate comprising a pluralitvof superimposed circular rings, the adjacent sides of which are provided with radial slots separated by narrower radial lands and means for holding said lands of one ring midway between the sides of said slots on the adjacent ring for the purpose of forming two slots of approximately the width of the interposed land in place of a single slot extending between a pair of adjacent lands.

, GORDON M. PELTZ. 

